Aspartyl (asparaginyl) β-hydroxylase (AAH) catalyzes post-translational hydroxylation of β carbons of specific aspartate and asparagine residues in epidermal growth factor-like domains of numerous proteins, including extracellular matrix proteins, low-density lipoprotein (LDL) receptor, Notch homologs, and Notch ligand homologs (Jia et al., Proc. Natl. Acad. Sci. USA 91(15):7227-7231, 1994; Jia et al., J. Biol. Chem. 267(20):14322-14327, 1992; Gronke et al., Proc Natl Acad Sci USA 86(10):3609-13, 1989). This transmembrane enzyme is a member of the α-ketoglutarate-dependent dioxygenase family of prolyl and lysyl hydroxylases. Overexpression of human AAH (HAAH) has been detected in a number of human cancers, including hepatocellular carcinomas, cholangiocarcinomas, and, neuroectodermal tumors (Lavaissiere et al., J. Clin. Investig. 98:1313-1323, 1996; Sepe et al., Lab. Investig. 82(7):81-891, 2002). The finding that AAH is overexpressed in numerous tumors, and that forced expression increases cell motility and survival indicates that AAH may contribute to malignant transformation in vivo (Sepe et al., Lab. Investig. 82(7):881-891, 2002).